Study On Microstructure And Thermal Deformation Behavior Of In-situ Autogenous Al 2 O 3 -TiC/Cu Composites By Hot Pressing Sintering

Al₂O₃/Cu composites are the most widely studied particle reinforced copper matrix composites,which has a good anti arc erosion and wear resistance and high strength.However,with the increasingly harsh application environment,for example,increase of the energy transmission density of the contact material and the miniaturization of the control parts and the increases of current density,the material of the anti-arc erosion put forward higher requirements.But the existing Al₂O₃/Cu composites are insufficient in resisting high temperature,high pressure and large arc load performance.TiC particles not only have excellent high-temperature strength,but also its anti-arc erosion performance and anti-wear properties are at a very high level.So there were have a potential use value in the harsh environments of conductivity,high temperature,arc erosion and abrasion that adding TiC particles into the Al₂O₃/Cu composites.In this paper,in situ Al₂O₃-TiC/Cu composites were prepared by spark plasma sintering?SPS?under Cu-Al-TiO₂-C system.XRD phase analysis and EDS energy spectrum analysis showed that Al₂O₃ and TiC particles were successfully synthesized by the in-situ reaction in the composites with dense tissue.The effects of the addition of?Al+TiO₂+C?,the addition of rare earth oxide CeO₂ and the sintering temperature on the microstructure and properties of Al₂O₃-TiC/Cu composites were analyzed.The results shows:?1?As the addition of?Al+TiO₂+C?increases,the strength of the composite increases,but the conductivity decreases.When the addition of?Al+TiO₂+C?is 8%,the conductivity and hardness of the composites are both in the superior value and the Vickers hardness value of the composites was HV154.6 and the conductivity was 53.0%IACS;?2?As the temperature increases,the conductivity of the composite also increases,but the strength is increased first and then descends.After the comprehensive consideration,the optimum sintering temperature is 980?,the conductivity of the composites is 19.2%IACS,the Vickers hardness is HV194.6;?3?CeO₂ in the composite is mainly to improve the surface tension of Cu matrix and increase the interface bonding strength with Al₂O₃ and TiC particles,and play the role of grain refinement.However,insufficient or excessive addition of CeO₂ has no significant or even adverse effect on the performance enhancement of Al₂O₃-TiC/Cu composites.The study shows that the hardness and electrical conductivity of the composites are increased obviously when the CeO₂ addition is 0.6%.In this study,The thermal compression deformation behavior of the Al₂O₃-TiC/Cu composites was studied by thermo physical simulation method.The thermal activation energy of the composites is calculated to be Q=361.161KJ/mol,and the constitutive equations of the flow stress of Al₂O₃-TiC/Cu composites are obtained to be:...